This invention relates to package terminal air conditioning units and in particular to a universal cabinet for housing component parts of an air conditioning system.
More specifically this invention relates to a package terminal air conditioning unit of the general type disclosed in U.S. Pat. No. 4,480,533. As noted in this patent these units, typically utilize free-standing low profile cabinets to house some or all of the component parts of an air conditioning system. The unit is designed to heat and/or cool a specific interior region of a building and is usually situated adjacent to an exterior wall of the building so that air can be exhausted through the wall to the outdoor atmosphere.
For the most part, most package terminal units are housed in extremely heavy and relatively bulky metal cabinets. The sheet metal panels are difficult to remove, as for example when periodic maintenance is to be performed, and the panels are easily dented and scratched when subjected to everyday use. More importantly however, the metal parts of the cabinet are continually exposed to condensate and liquid refrigerants which promote rapid oxidation of metals. As a consequence the metal cabinets become rusted and unsightly and eventually must be replaced.
The air handling characteristics of most metal cabinets have also been found to be relatively poor. The air passages are formed of sheet metal with little or no concern given to the aerodynamic properties of the system or the air handling properties of the fan. The fan is usually hung at some convenient place within the duct work. Movement of air through the unit is thus inefficient thereby adversely effecting the overall performance of the air conditioning system. These cabinets are also limited as to use in that they are dedicated in design to one particular air conditioning system and cannot be adapted for use with others.